The amount that an 8 pound rifle shooting a 150 grain bullet moves back when the bullet reaches the end of a 24 inch barrel is about 1/16 of an inch.
The rest of the recoil, and most of the recoil the shooter feels is the force needed to arrest the momentum of the gun after that short 1/16 of an inch of rearward acceleration.
A muzzle brake allows the powder gasses to arrest that rearward momentum so your shoulder doesn't have to.